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...bution function (Eq. 2), quantities involving average values of the chain tilt angle b can be calculated, such as the chain orientational order parameter Sx-ray, defined as Sx-ray 1 2 ð3Æcos2bæ 1Þ: =-=(5)-=- Depending upon the value of m in Eq. 2, Sx-ray can take on values from 0 to 1, with Sx-ray 1 (m infinity) corresponding to all chains aligned along the bilayer normal and Sx-ray 0(m 0) correspo...

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...ively. Sphingolipids have saturated tails that allow them to be in a more packed configuration, with cholesterol filling the spaces between the acyl chains and increasing the density of lipid packing =-=[3,4]-=-.INTRODUCTION 2 Sterols are the major non polar lipids of cell membranes, with cholesterol predominating in mammals and ergosterol in yeast. They are based on a planar and rigid four-ring structure. ...

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...s weaker than that observed for single-component membranes, where the area condensation is shown to be around 10%–20% for 30% cholesterol (in experiments and simulations done at a slightly higher RH) =-=[62,63]-=-. Our data, again, suggest that the ordering brought about by cholesterol is not as complete in the five-component membrane as in homogeneous one-component membranes. Cholesterol also affects the lipi...

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...nalty is also quadratic in the spontaneous curvature of the PE, which increases with the disorder of its tails. But cholesterol is known to decrease the disorder of hydrocarbon tails of phospholipids =-=(21)-=-. In particular, in excess of 0.35 mol fraction cholesterol, palmitoyloleoylphosphatidylethanolamine (POPE) bilayers are very well ordered, comparable to those of palmitoyloleoylphosphatidylcholine, (...

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...e lipid area,sknown as the cholesterol condensing effect.sThe thickening effect of cholesterol wassreported by Levine and Wilkins (1971) for egg lecithin and has been measured forsvarious lipids (see =-=Hung et al., 2007-=- and the references therein).sHung et al. (2007)shave shown that the bilayer thickness increases and the lipid area decreasesssubstantially with the addition of cholesterol to DOPC.sThey report 72 Å2 ...

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...ch has similar cross-sectional area (~56.0 Å2 per AmB) (39) as compared to the experimental values for a pure DMPC bilayer and a 7:3 DMPC/Cho mixture (~60.0 Å2 and ~45.0 Å2 per DMPC, respectively) =-=(40,41)-=-. The dimers were placed in a manner consistent with the putative mechanism of action of AmB, that is, with the AmB polar head (Fig. 1A) located at the bilayer/water interface and the lactone ring bur...

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...biotics and cholesterol with the multilamellar bilayer were different. Our previous reports indicated that cholesterol molecules inserted into the lipid bilayer [41,42] and increased the PtP distance =-=[43]-=-. Other studies by us also indicated that peptides lay horizontally on the membrane outer surface, which shortens the PtP distance [44,45]. Similarly, Fig. 4 confirms that penicillin and sulbactam bot...

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...(A) A GUV with red dye in the lipid and green dye in its content wassexposed to 5 11M LL-37. Leakage occurred stochastically. (1) t = 0, right beforesleakage occurred. (2) t = 30 sec. (3) t = 60 sec. =-=(4)-=- t = 300 sec, the GUVwas stillsintact. In 60 sec, the leakage reduced the content dye intensity to -10°/o of thest = 0 value, while photo-bleaching decreased the intensity of a non-leakingsGUV to -90°...